Explosive holder for seismic prospecting



Sept 19, 1967 T. E. MILLER ETAL EXPLOSIVE HOLDER FOR SEISMIC PROSPECTING2 Sheets-Sheet l Filed March 8, 1966 sept. 19, 1967 EXPLOS IVE FiledMarch 8, 1966 MQW/@W vavN//w//s Fig.8

T. E. MILLER ETAL. 3,342,130

HLDER FOR SEISMIC PROSPECTING 2 sheets-sheet'z Fig. 7

. 7. Thomas E. Miller William A. Parker INVENTORS United States Patent3,342,130 EXPLOSIVE HOLDER FOR SEISMIC PROSPECTING Thomas E. Miller, ElCentro, Calif. (731 Poplar, Wasco,

Calif. 93280), and William A. Parker, El Centro,

Calif. (2109 1st St., P.O. Box 296, Wasco, Calif.

Filed Mar. 8, 1966, Ser. No. 532,727 7 Claims. (Cl. 102-21.8)

ABSTRACT OF THE DISCLOSURE A holder adapted to position an explosivecharge within a borehole which holder comprises a tubular body memberadapted to support the explosive `charge by the provision of upwardlyand downwardly projecting resilient borehole wall gripping membersadapted to normally preclude upward or downward movement of the holdersubsequent to its being set at a predetermined position in the borehole.

The present invention relates to explosive holders and more specificallyto explosive holders adapted to selectively secure a suitable charge ofexplosive at a predetermined point within a borehole such as is normallyutilized in conjunction with a seismic prospecting procedure. Moreparticularly, the present invention relates to an explosive holder ofthe class described which is adapted to secure an explosive chargewithin a borehole in such a manner so as to resist movement of thecharge by an explosion or implosion caused by the detonation of anothercharge of explosive within the borehole.

Numerous devices have been proposed heretofore to facilitate placementof an explosive charge within a borehole. However, many such devices areunduly cumbersome, complicated and do not properly anchor the explosivecharge so as to substantially resist movement of the charge due to theforces exerted by the detonation of another explosive charge within theborehole.

It is therefore a primary object of the present invention to provide anexplosive charge holder adapted to selectively position an explosivecharge within a borehole such as utilized in a seismic prospectingprocedure.

Another object of the present invention is to provide an explosivecharge holder adapted to selectively position an explosive charge withina borehole, which 'holder is provided with means engaging the boreholewall to preclude displacement of the explosive charge holder due to theforces exerted by the detonation of a second explosive charge within theborehole.

A further object of the present invention is to provide an explosivecharge holder for seismic prospecting and the like which is adapted tobe utilized in conjunction with explosive charges such as stickdynamite, as well as explosive lled containers such as metal canswherein a plurality of cans may be threadably coupled to vary thecharge.

Still another object of the present invention is to provide an explosivecharge holder which comprises a generally cup-shaped body memberprovided with a plurality of rigidly secured spring steel membersadapted to engage the'borehole wall in a manner so as to precludedisplacement ofthe charge holder from its predetermined position withinthe borehole.

Still a further object of the invention is to provide an explosivecharge holder of the class described wherein the borehole wall engagingmeans utilized to secure the charge holder is further provided with arestraining means to selectively prevent engagement of one or more ofthe borehole wall engaging means with the borehole wall so as tofacilitate placement of the exploisve charge at a ICC predeterminedpoint within the borehole after which the restrained borehole wallengaging means may be released from above ground to permit the boreholewall engaging means to grip the borehole wall.

These together with other objects and advantages which will becomesubsequently apparent reside in the details of construction andoperation as more fully hereinafter described and claimed, referencebeing had to the accompanying drawings forming a part hereof, whereinlike numerals refer to like parts throughout, and in which:

FIGURE 1 is a side elevational view showing one ernbodiment of anexplosive charge holder constructed in accordance with the presentinvention positioned at the bottom of as well as at an intermediatepoint within a seismic prospecting borehole;

FIGURE 2 is an enlarged side elevational view of the charge holdingdevice of FIGURE 1 further showing the method and means of selectivelyrestraining certain of the elements `comprising the anchoring means soas to permit placement of the charge holder within the borehole;

FIGURE 3 is a perspective view of the explosive charge holder of FIGURE2;

FIGURE 4 is an enlarged horizontal sectional view of the charge holderof FIGURE 1 taken substantially along the plane of line 4 4 of FIGURE l;

FIGURE 5 is an enlarged fragmentary side elevational View takensubstantially along the plane of line 5 5 of FIGURE 2 showing details ofthe manner in which a plurality of explosive lled containers are securedto the body `rof the charge holding device;

FIGURE 6 is a fragmentary side elevational View of a further embodimentof an explosive charge holder constructed in accordance with the presentinvention which holder is primarily adapted to be utilized inconjunction with stick dynamite and the like;

FIGURE 7 is a side elevational view of the explosive charge holder ofFIGURE 6; and

FIGURE 8 is a top plan view of the explosive charge holder of FIGURE 7.

Referring now to the drawings in detail and FIGURES 1 through 5 inparticular, it will be seen that the embodiment of the present inventionillustrated therein cornprises an explosive charge holder indicatedgenerally at 10 which is positioned within a borehole 11 in engagementwith the borehole wall 13. The holder 10 includes a generally cup-shapedbody member 12 having a generally tubular vertically disposed side wallportion 14 and a horizontally disposed bottom wall portion 16.

As see-r1 best in FIGURE 5, the bottom wall portion 16 is provided witha centrally disposed aperture as indicated at 18 to facilitate securinga plurality of explosive lled containers such as 20 adapted to bethreadably connected in contiguous longitudinally extendingrelationship. As also seen best in FIGURE 5, each of the explosive lledcontainers 20 is provided with a threaded male portion 22 at one end ofthe container and a threaded female connection as indicated, at 24 atthe opposite end of the container, the inner diameter of which iscomplementary to the outer diameter of the threaded male connection 22.Thus, as seen in FIGURE 5 a plurality of explosive lled containers 20may be secured to the body member 12 of the explosive charge holder 10by inserting the male connection 22 of a container 20 upwardly throughthe aperture 18 in the bottom wall portion 16 of the body member 12 andthen threadably tightening a second container 20 of explosive onto theabove-mentioned container 20 by engaging the threaded female connector24 with the male connector 22 projecting upwardly through the aperture18. In a similar fashion the desired number of explosive holdingcontainers may be secured in rupwardly and down-` wardly extendingrrelationship to the first' two containers f 20 secured to the bodymember 12.

As further seen in FIGlURE 2y the` charge comprised of a pluralityof'interconnected explosive filled containersy n above ground.

It will be further noted that the explosive charge holder 10 includes astabilizing means indicated generally at 3f) which includes a pluralityof arcuate yrelatively rigid resilient gripping members 32 which karesecured such as at 34 to the body member 12 intermediate of the endsthereof by means' of welding for example so as to provide a f pluralityof outwardly diverging fingers adapted tor engage the wall 13oftheborehole 11. The arcuaterelaktively rigidy resilient 'members 32are prefer'ably,falthough notnecessarily, formedof spring steel forexample.y And with` an upwardly, longitudinally extending explosivecharge positioning means which includes a rigid `rod or n tube 140rigidly secured to the body member 112 by means of welding or the like.The rod 140 is further provided with one or more spring clips 142 whichpass` about the rod 140 and a stick of dynamite 120,y as seenk best in,FIGURE 6, thereby frictionally retaining the dynamite 120 to they rod140 The fuses 144 of the dynamite 120 are connected in a suitable mannerto a squib device,

not shown, in order to facilitate' detonation of the ex' plosive.Although not shown, it will kbe understood that the relatively rigidarcuate resilient gripping members -132 maybe restrained in an inwardlydisposed position by a restraining means analogous to the means 40illustrated in connection with the embodiment of the invention kShown inFIGURE 2.

as seen best iny FIGURE 4, the ends of the members 32 are cut at 'adiagonal so asto provide sharp points such asat 33 tofacilitatepenetration of the borehole wall 13 to aid in precludingmovement ofthe positioned charge.

` y practice of thek presentinventionis thought to be obviousy Referringnow 'to FIGURE 2, it will be seen that the lectively f releasablerestraining means indicated generally at which is adapted to restraintwo'or more of .ther outwardlydivergingends ofthearcuate members 32yinwardly out of engagement with the wall 13. Towards this end, severalplies of a .plastic'orv 'cloth'adhesive tape 42r y y v members 132 aretaped together such as with tape 42 tok n restrain the points 33 so'asto prevent their engagementr are wrapped about the outer ends of themembers 32 to form a continuous loop thereabout, as seen in FIGURE 2.The tape is preferably notched as 'at 44 to facilitate severingthereofand the restraining means 40 is further proexplosivecharge holder 10kmay kbe provided with a sef Itwill be further understoodthat the clipsk142 may alternately be rigidly secured to the rod 140 at appro-y priate`points kalong the lengthy thereofy ydepending uponv the length of thestickexplosive utilized. n n n n Although the method of utilizing theexplosive charge holders 1.6 and 100 constructed in accordance with thefrom the foregoing, the method of utilization thereof will be brieflydescribed. As seen best in FIGURES l and 2,

in order to place a .plurality of Lexplosive charges within a borehole,such as is normallyy done in a seismic prosn pecting. procedure, 'anappropriate number of containers ofk explosive 26 are secured to theexplosive charge holder vided with a severingy means indicated at 46which includes a wire clip 48 which is formed from a continuous theconnection of an actuating line 50 thereto to permit severing of thetape 42 from above ground by pulling upon the line 50 to release thearcuate gripping members 32 to engage the borehole wall 13.

Referring now to the embodiment of the present invention shown inFIGURES 6-8, it will be seen that the explosive charge holder indicatedgenerally at 100 includes a generally cup-shaped body member indicatedgenerally at 112. As seen best in FIGURES 7, the body member 112includes a generally tubular vertically disposed side wall portion 140`and an imperforate bottom wall portion 160. In the embodiment shown, thebody member 112 is sized so as to receive the end of a stick of dynamitesuch as indicated at 120, however, it will be understood that the innerdiameter of the body member 112 may be of any suitable dimension toaccept other forms of explosives.

The explosive charge holder 100 is further provided with stabilizingmeans indicated generally at 130 which includes a plurality ofrelatively rigid arcuate resilient gripping members 132 which arerigidly secured to the body member 112 such as at 134 by means ofwelding for example.

As seen best in FIGURES 6 and 7 the arcuate members 132 are preferablysecured to the body member 112 intermediate of their ends so as toprovide a plurality of youtwardly diverging fingers which projectupwardly and downwardly relative to the body member 112 and are thusadapted to frictionally and positively engage the Wall 13 of theborehole 11. Toward this end, the arcuate gripping members 132,preferably formed of spring steel or the like, are cut diagonallyadjacent their ends so as t0 provide sharp points 133 adapted to gripthe wall 13 of the borehole 11.

The CXPlOSiV .Charge hOlder 100 is further provided kklength ofwirepassed aboutthe tape 42 which'wire is f alsofbentto rprovide a loopat the top thereof to facilitate 4G` 10, with a detonating device 26secured to the top thereof. To place the lowermost charge, as seen inFIGURE l,

the downwardly projecting arcuate resilient gripping with the boreholewall k13a asthe ,charge is pushed downwardly in the borehole'll suchaswith a loading pole restrained arcuate resilient gripping members 32engaging the borehole wall 13.

The uppermost charge as seen in FIGURE 1, which also includes aplurality of explosive filled containers 20 secured to an explosivecharge holder 10, is placed within the borehole by first providing theexplosive charge holder 10 with the restraining means 40 illustrated inFIGURE 2 so as to permit placement of the explosive charge within theborehole 11 with a loading pole such as 80. When the charge has beenpushed to the appropriate point within the boreole 11, which is normallyat a point spaced apart from the lowermost charge, the control cable 50is pulled to sever the tape 42 thus permitting the downwardly projectingportions of the arcuate resilient gripping members 32 to assume theposition shown in FIGURE 1 thus securing the uppermost charge in amanner so as to preclude its displacement from the predeterminedposition by the forces created on the detonation of the lowermost chargeat the bottom of the borehole 11.

It will therefore be seen that when the lowermost charge in the boreholeis detonated the sudden expansion of air within the borehole 11 will notsubstantially displace the uppermost charge due to the fact that thearcuate resilient upwardly projecting portions of the gripping members32 engage the borehole wall 13. In a similar fashion, when the airrushes downwardly within the borehole 11 subsequent to the detonation ofthe lowermost charge the uppermost charge will not be displaceddownwardly due to the fact that the downwardly projecting portions ofthe arcuate resilient gripping members 32 likewise engage the wall 13 ofthe bore-hole 11.

It will therefore be seen that there has been provided an explosivecharge holder which satisfies the objects of the present invention andovercomes the shortcomings of many explosive charge holders proposedheretofore. Al-

though not specically discussed, it will nevertheless be understood thatthe method of utilizing the embodiment of the explosive charge holder100 shown in FIGURES 6-8 is similar to that discussed with the exceptionthat dynamite sticks are utilized instead of explosive filledcontainers.

The foregoing is considered as illustrative only of the principles ofthe invention. Further, since numerous modications and changes willreadily occur to those skilled in the art, it is not desired to limitthe invention to the exact construction and operation shown anddescribed, and accordingly all suitable modifications and equivalentsmay be resorted to, falling within the scope of the invention asclaimed.

What is claimed as new is as follows:

1. In combination with an explosive charge, a holder adapted to positionthe explosive charge within a borehole which comprises a generallytubular cup-shaped body member adapted to receive at least a portion ofthe explosive charge, stabilizing means secured to said body member andadapted to selectively position the holder within a borehole by grippingthe wall of the borehole and adapted to normally stabilize the holderagainst both upward and downward movement in the borehole, saidstabilizer means including a plurality of upwardly and downwardlydiverging relatively rigid resilient borehole wall gripping membersadapted to normally secure said holder within a borehole at apredetermined point, whereby said holder will be held relativelystationary against upward and downward movement in the borehole duringdetonation of another explosive charge spaced from the charge held bysaid explosive holder.

2. The combination of claim 1, wherein said body member is an upwardlyopening cup-shaped member including a bottom wall portion provided withan aperture whereby a plurality of explosive lled containers providedwith complementary threaded coupling members may be secured to saidcup-shaped member by interposing said apertured bottom portion betweentwo threadably coupled explosive filled containers.

3. The combination of claim 1 wherein said body member is an upwardlyopening cup-shaped member having an imperforate bottom adapted toreceive the lower end of a stick of dynamite and the like, said holderincluding an upwardly extending rod rigidly secured to said body member,said rod being provided with clip means adapted to grippingly engage thestick of dynamite.

4. The combination of claim 1 wherein said holder includes a selectivelyreleasable restraining means adapted to restrain at least saiddownwardly diverging gripping members out of engagement with theborehole to facilitate placement of the charge holder at a predeterminedpoint within the borehole, said restraining means including a continuousloop of severable tape, said tape being positioned about said grippingmembers, and severing means coacting with said tape and operable `fromabove ground to sever said tape to release said gripping members intoengagement with the borehole wall.

5. The combination of claim 1, wherein said outwardly projecting ngerscomprise arcuate spring metal gripping members rigidly secured to saidbody member intermediate their ends.

6. The combination of claim S, wherein the ends of the arcuate springmetal members are provided with sharp points adapted to assist inengaging the borehole wall.

7. An explosive holder adapted to position an explosive charge within aborehole which comprises a generally tubular cup-shaped body memberadapted to receive at least a portion of the explosive charge,stabilizing means secured to said body member and adapted to selectivelyposition the holder within a borehole by gripping the wall of theborehole and adapted to normally stabilize the holder against bothupward and downward movement in the borehole, said stabilizer meansincluding a plurality of upwardly and downwardly diverging relativelyrigid resilient borehole wall gripping members adapted to normallysecure said holder within a borehole at a predetermined point, wherebysaid holder will be held relatively stationary against upward anddownward movement in the borehole during detonation of another explosivecharge spaced from the charge held by said explosive holder.

References Cited UNITED STATES PATENTS 1,220,208 3/1917 Ellis l02-241,560,815 l1/1925 Hill IGZ-21.8 X 2,450,366 9/1948 Williams 102-21.8 X2,965,031 12/1960 Johns 175--4.52 3,046,886 7/1962 Joslin IGZ-21.8

BENJAMIN A. BORCHELT, Primary Examiner. V. R. PENDEGRASS, AssistantExaminer.

1. IN COMBINATION WITH AN EXPLOSIVE CHARGE, A HOLDER ADAPTED TO POSITIONTHE EXPLOSIVE CHARGE WITHIN A BOREHOLE WHICH COMPRISES A GENERALLYTUBULAR CUP-SHAPED BODY MEMBER ADAPTED TO RECEIVE AT LEAST A PORTION OFTHE EXPLOSIVE CHARGE, STABILIZING MEANS SECURED TO SAID BODY MEMBER ANDADAPTED TO SELECTIVELY POSITION THE HOLDER WITHIN A BOREHOLE BY GRIPPINGTHE WALL OF THE BOREHOLE AND ADAPTED TO NORMALLY STABILIZE THE HOLDERAGAINST BOTH UPWARD AND DOWNWARD MOVEMENT IN THE BOREHOLE, SAIDSTABILIZER MEANS INCLUDING A PLURALITY OF UPWARDLY AND DOWNWARDLYDIVERGING RELATIVELY RIGID RESILIENT BOREHOLE WALL GRIPPING MEMBERSADAPTED TO NORMALLY SECURE SAID HOLDER WITHIN A BOREHOLE AT APREDETERMINED POINT, WHEREBY SAID HOLDER WILL BE HELD RELATIVELYSTATIONARY AGAINST UPWARD AND DOWNWARD MOVEMENT IN THE BOREHOLE DURINGDETONATION OF ANOTHER EXPLOSIVE CHARGE SPACED FROM THE CHARGE HELD BYSAID EXPLOSIVE HOLDER.